Li Gaoshan, a 90-year-old survivor of the Nanjing Massacre in World War II, on Sunday pressed a button to launch cngongji.cn, a website designed to promote commemoration of the tragedy.

In February, China's top legislature set December 13 as a national memorial day for Nanjing Massacre victims. Previously, memorial services were mostly limited to the province of Jiangsu, where Nanjing is located.

The launch of the website will lead a series of commemoration activities preluding the first national memorial later this year.

The website in three languages -- Chinese, Japanese and English -- is sponsored by the Nanjing Massacre Memorial Hall and Xinhua News Agency.

Russian, French, German and Korean-language editions will be added to the site by the Dec. 13 memorial service, said the sponsors.

"The site was built to popularize China's national memorial activities, helping people understand the history and commemorate those killed by Japanese invaders during World War II," said Zhu Chengshan, curator of the Nanjing Massacre Memorial Hall.

He said that interaction is one of the main characteristics of the website, which has an area that lets netizens virtually light candles, present flowers, plant trees and ring bells for mourning war victims.

The website also introduces memorial activities in other countries.

Monday will coincide with the 77th anniversary of the July 7 Incident which marked the beginning of China's War of Resistance Against Japanese Aggression.

Seven decades after the brutal war (1937-1945), survivors of it are dying of old age. During the Nanjing Massacre, Li Gaoshan was only 13-year-old. He witnessed Japanese soldiers using machine guns to slaughter unarmed civilians after the city of Nanjing fell into the enemy's hands.

Li is among about 100 such eyewitnesses. The memorial hall on Sunday invited relatives and friends of the victims to share information on those killed in the massacre.

According to China's official records, more than 300,000 civilians and soldiers died in the massacre, which began on Dec. 13, 1937 and lasted for six weeks.

While Japanese historians and politicians call that number into question, the Chinese data was confirmed by the International Military Tribunal for the Far East and the Nanjing War Crimes Tribunal, according to Zhu.

Also on Sunday, the first album of documents relating to the National Memorial Day including the legislation bill, its referred historical data and media reports was published in Nanjing.